1. Field of the Invention
The present invention relates to a stator of an electric rotating machine, and an electric rotating machine having the stator.
2. Description of Related Art
In recent years, there is a growing need of electric rotating machines usable as electric motors or generators which are compact in size and of high quality.
For example, an electric rotating machine mounted on a vehicle is required to generate more output power because of an increase of vehicle loads, although the space assigned to mount the electric rotating machine in an engine compartment is becoming smaller.
As described, for example, in Japanese Patent No. 3604326, there is known a compact and high-output electric rotating machine having a structure in which the resistance of phase windings thereof is small, the lamination factor of electric conductors accommodated in the magnetic circuit of a stator thereof is large, and the turn portions of the phase windings are in proper alignment and wound densily.
This patent document describes, as an assembling method of the stator, a step of preparing a stator winding of a predetermined shape by winding pillar-conductors in the circumferential direction a plurality of times so as to be laminated in the slot direction (in the radial direction), a step of disposing a plurality of divided cores in a ring around the outer periphery of the stator winding in a state of being overlapped at their lap portions, a step of moving the divided cores radially inwardly so that they are inserted into the stator winding, and a step of fixing the divided cores to one another.
However, the stator of an electric rotating machine of the type in which its stator core is constituted by a plurality of divided cores has a problem in that it is difficult for the electric rotating machine to output a sufficiently large power, because the divided portions (surfaces of the divided cores) have a magnetic resistance.
Although the above patent discloses reducing the magnetic resistance by the provision of the lap portions, the effect is restrictive.
In addition, there is another problem that an eddy current occurs in each lap portion, causing iron loss (core loss) to increase.